By CBS3 Staff

PHILADELPHIA (CBS) – Two children, including a 1-year-old girl, were injured in a house fire in Philadelphia. The fire broke out around 12:30 a.m. Friday on the 1500 block of West Butler Street in Nicetown.

Firefighters say they arrived to find heavy smoke on the second floor.

READ MORE: 4 People Shot In Drive-By Shooting During Sidewalk Sale In Franklinville, Philadelphia Police Say

1-Year-Old, 12-Year-Old Children Injured In Nicetown House Fire

READ MORE: MAGA Hat Theft At Last Year's Democratic National Convention In Wilmington Leads To Hate Crime Plea

They worked quickly to put out the flames.

The little girl was transported to the hospital with third-degree burns and a 12-year-old was treated at the scene.

MORE NEWS: WATCH LIVE: Delaware Gov. Carney To Hold Virtual Press Briefing On COVID-19

The cause of the fire is under investigation.